2.1 Field of Technology
The present technology relates to a patient interface used for Non-invasive Positive Pressure Ventilation (NPPV) and for continuous positive airway pressure (CPAP) therapy of sleep disordered breathing (SDB) conditions such as obstructive sleep apnea (OSA).
2.2 Description of Related Art
Treatment of sleep disordered breathing (SDB), such as obstructive sleep apnea (OSA), by continuous positive airway pressure (CPAP) flow generator systems involves the continuous delivery of air (or other breathable gas) pressurized above atmospheric pressure to the airways of a human or other mammalian patient via a conduit and a mask. Pressurized air is delivered to the mask by a conduit connected to the CPAP device and the mask.
Upper airway resistance during sleep and the propensity to obstructive sleep apnoea are said to be significantly lower while breathing nasally rather than orally. See Fitzpatrick et al. Eur Respir J 2003; 22: 827-832.
While healthy subjects with normal nasal resistance are said to breathe almost exclusively through the nose during sleep, some patients nevertheless experience mouth breathing or occasional mouth leaks if they wear nasal-only masks, and such mouth breathing or mouth leak can be uncomfortable and/or reduce the effectiveness of treatment.
To address this, patients may use chin straps or tape to block the mouth. Other patients may use a nose and mouth, or full-face mask and receive pressurized air flows to the airways via the nose and mouth.
U.S. Pat. Nos. 5,560,354 and 6,123,071 (both to Berthon-Jones, and assigned to ResMed Limited) disclose a combination mouth and nasal mask for assisted respiration of CPAP.
EP Patent 2020978 (Respcare) is said to disclose a hybrid ventilation mask with a nasal interface and method for configuring such a mask.
International Patent Application No. PCT/AU2006/001246 published as WO 2007/025329 (to Frater et al., and assigned to ResMed Limited) discloses a mouth seal assembly for a nasal mask system to prevent mouth breathing.
International Patent Application No. PCT/AU2010/000381 published as WO 2010/111749 (to Frater, and assigned to ResMed Limited) discloses a nasal mask system including an interface adapted to form an air interface with a patient's nose, and a mouth seal adapted to form a seal with the patient's mouth to reduce or eliminate mouth breathing.